Two new temperature-controlled chambers were constructed and evaluated. The new units incorporated a linear feedback sensor and bipolar power supply to allow regulation at any temperature between -3 deg. C and +85 deg. C. The set temperature is entered via a 3-digit thumb wheel switch and the sample temperature is read out on a 3 1/2 digit display. The time required for 95% response to a 10 deg. C change in the set temperature is approximately 70 seconds. The time required for 95% response to a change from 0 deg. C to 70 deg. C is approximately 300 seconds. At equilibrium, the baseline stability is +/- 15 milli-deg. C. Two types of cells were developed to contain the sample under investigation. The first is a simple closed cell in which the sample solution is sealed between two mylar wafers in an aluminum cell. The second type of cell is open and can be flushed during runs without removal from the chamber.